AIDL (Android Interface Definition Language) is similar to other IDLs you might have worked with. It allows you to define the programming interface that both the client and service agree upon in order to communicate with each other using interprocess communication (IPC)
Firebase is a mobile platform that helps you quickly develop high-quality apps, grow your user base, and earn more money. Firebase is made up of complementary features that you can mix-and-match to fit your needs.
To maintain security for the system and users,Android requires apps to request permission before the apps can use certain system data and features. Depending on how sensitive the area is, the system may grant the permission automatically, or it may ask the user to approve the request
If the device is running Android 6.0 or higher, and your app target SDK is 23 or higher: The app has to list the permissions in the manifest, and it must request each dangerous permission it needs while the app is running
View is the base class for widgets, which are used to create interactive UI components (buttons, text fields, etc.)
The ViewGroup subclass is the base class for layouts,which are invisible containers that hold other Views (or other ViewGroups) and define their layout properties
Widgets are an essential aspect of home screen customization. You can imagine them as "at-a-glance" views of an app most important data and functionality
Every application must have an AndroidMenifest.xml file (with precisely that name) in its root directory. The manifest file provides essential information about your app to the Android system, which the system must have before it can run any of the applications code.